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schizophrenia

  • by Paul Armentano, NORML Deputy Director August 26, 2015

    Latest JAMA Studies Largely Fail To Support Past Claims About Marijuana And Brain HealthTwo new studies published online today in JAMA (Journal of the American Medical Association) Psychiatry provide little support for previous claims that cannabis exposure is significantly harmful to the developing brain.

    The first study, which assessed the effects of cannabis exposure on brain volume in exposed and unexposed sibling pairs, reported that any identifiable differences “were attributable to common predispositional factors, genetic or environmental in origin.” By contrast, authors found “no evidence for the causal influence of cannabis exposure” on brain morphology.

    The trial is “the largest study to date examining the association between cannabis exposure (ever versus never used) and brain volumes.”

    The study is one of two recent clinical trials to be published in recent months rebutting the claims of a widely publicized 2014 paper which alleged that even casual marijuana exposure may be linked to brain abnormalities, particularly in the region of the brain known as the amygdala. In January, researchers writing in The Journal of Neuroscience reported “no statistically significant differences … between daily [marijuana] users and nonusers on [brain] volume or shape in the regions of interest” after researchers controlled for participants’ use of alcohol. Similarly, today’s JAMA study “casts considerable doubt on hypotheses that cannabis use … causes reductions in amygdala volumes.”

    A second study appearing today in the journal assessed whether cannabis use during adolescence is associated with brain changes that may be linked to an increased risk of schizophrenia. While researchers reported finding an association among male subjects who possessed a high genetic predisposition toward schizophrenia, authors reported that no such association existed among male subjects who were at low risk for the disease, or among females in either the high risk or low risk categories. The finding is consistent with the theory that early onset cannabis use may potentially exacerbate symptoms in a minority of subjects predisposed to the disease, but it contradicts claims that marijuana exposure is a likely cause of schizophrenia, particularly among those who are not already vulnerable to the disease.

    Abstracts of both new studies appear online in JAMA Psychiatry here and here.

  • by Paul Armentano, NORML Deputy Director February 24, 2015

    NORML Responds To Marijuana And Psychosis ClaimsLast week, in what is becoming a semi-annual mainstream media ritual, news outlets around the globe published sensational headlines alleging that consuming cannabis will drives people crazy.

    On Monday, I published a rebuttal of these claims in a commentary published on the website Alternet.org — an excerpt of which appears below.

    Debunking the Latest Pathetic Fear Smear Campaign Against Marijuana

    [excerpt] [N]umerous (though far less publicized) studies have come to light downplaying the likelihood that cannabis use is a direct cause of psychiatric disorders like schizophrenia. Specifically, a 2009 paper in the journal Schizophrenia Research compared trends in marijuana use and incidences of schizophrenia in the United Kingdom from 1996 to 2005. Authors reported that “incidence and prevalence of schizophrenia and psychoses were either stable or declining” during this period, even though pot use among the general population was rising. They concluded: “This study does not therefore support the specific causal link between cannabis use and incidence of psychotic disorders. … This concurs with other reports indicating that increases in population cannabis use have not been followed by increases in psychotic incidence.”

    Similarly, a 2010 review paper published by a pair of British scientists in the journal Addiction reported that clinical evidence indicating that use of he herb may be casually linked to incidences of schizophrenia or other psychological harms is not persuasive. Authors wrote: “We continue to take the view that the evidence that cannabis use causes schizophrenia is neither very new, nor by normal criteria, particularly compelling. … For example, our recent modeling suggests that we would need to prevent between 3000 and 5000 cases of heavy cannabis use among young men and women to prevent one case of schizophrenia, and that four or five times more young people would need to avoid light cannabis use to prevent a single schizophrenia case. … We conclude that the strongest evidence of a possible causal relation between cannabis use and schizophrenia emerged more than 20 years ago and that the strength of more recent evidence may have been overstated.”

    More recently, researchers at Harvard University released a study further rebutting this allegation. Writing in 2013 in Schizophrenia Research, investigators compared the family histories of 108 schizophrenia patients and 171 individuals without schizophrenia to assess whether youth cannabis consumption was an independent factor in developing the disorder. Researchers reported that a family history of schizophrenia increased the risk of developing the disease, regardless of whether or not subjects consumed weed as adolescents. They concluded: “The results of the current study, both when analyzed using morbid risk and family frequency calculations, suggest that having an increased familial risk for schizophrenia is the underlying basis for schizophrenia in these samples and not the cannabis use. While cannabis may have an effect on the age of onset of schizophrenia it is unlikely to be the cause of illness.”

    In fact, some researchers speculate that specific cannabinoids, such as cannabidiol (CBD), may even be efficacious in treating symptoms of psychosis. According to a review published in the January 2014 issue of the journal Neuropsychopharmacology: “CBD has some potential as an antipsychotic treatment. … Given the high tolerability and superior cost-effectiveness, CBD may prove to be an attractive alternative to current antipsychotic treatment.” Specifically, a 2012 double-blind, randomized placebo-controlled trial assessing the administration of CBD versus the prescription anti-psychotic drug amisulpride in 42 subjects with schizophrenia and acute paranoia concluded that two substances provided similar levels of improvement, but that cannabidiol did so with far fewer adverse side effects.

    Case reports in the scientific literature also indicate that some patients turn to cannabis for subjective benefits, though other studies indicate that pot use may exacerbate certain symptoms in patients with psychiatric disorders. Nonetheless, even a recent paper summarizing the “adverse health effects of recreational cannabis use” acknowledges, “It is difficult to decide whether cannabis use has had any effects on psychosis incidence, because even if a relationship were to be causal, cannabis use would produce a very modest increase in incidence.”

    You can read my full commentary here.

    You can also watch my discussion with Thom Hartmann of The Big Picture (air date: February 23) here.

  • by Paul Armentano, NORML Deputy Director December 16, 2013

    Cananbidiol (CBD), a non-psychotropic cannabinoid, alleviates psychotic symptoms and may hold promise as an alternative antipsychotic treatment, according to a review published in the November issue of the journal Neuropsychopharmacology.

    Investigators in the Netherlands and in the United Kingdom reviewed preclinical and clinical data on the use of CBD as an antipsychotic agent. Authors reported that both animal and human studies document the ability of CBD to mitigate symptoms of psychosis. Specifically, CBD administration is associated with improved symptoms in clinical evaluations of patients with schizophrenia, Parkinson’s disease, and ketamine-induced dissociative and psychotic symptoms.

    Investigators also highlighted a 2012 double-blind, randomized placebo-controlled trial assessing CBD versus the prescription anti-psychotic drug amisulpride in 42 subjects with schizophrenia and acute paranoia. Authors reported that both CBD and the prescription drug were associated with “equally significant clinical improvement” in this patient population, but that cannabidiol “possessed significantly less side effects.”

    Researchers concluded: “[E]vidence from several study domains suggests that CBD has some potential as an antipsychotic treatment. … Given the high tolerability and superior cost-effectiveness, CBD may prove to be an attractive alternative to current antipsychotic treatment.”

    Previous human trials assessing the administration of CBD in healthy human subjects report that the cannabinoid is “safe and well tolerated.”

    Separate investigations of CBD, primarily in animal models, have documented the cannabinoid to possess a variety of therapeutic qualities, including anti-inflammatory, anti-diabetic, anti-epileptic, anti-cancer, and bone-stimulating properties. Recently, the FDA approved the experimental use of CBD extracts for the treatment of a rare form of intractable pediatric epilepsy known as Dravet syndrome. Preliminary clinical trials assessing the safety and tolerability of the compound in children are scheduled to begin imminently.

    Full text of the study, entitled “Cannabidiol as a potential treatment for psychosis,” appears online here.

  • by Erik Altieri, NORML Executive Director June 1, 2012

    This Week in Weed

    Click here to subscribe to NORMLtv and receive alerts whenever new content is added.

    The latest installment of “This Week in Weed” is now streaming on NORMLtv.

    This week: A new study shows cannabis use decreases mortality rate in patients with schizophrenia and related ailments and Rhode Island’s Governor signs a bill allowing for “Compassion Centers.”

    [youtube]http://www.youtube.com/watch?v=Ze14eG39at0[/youtube]

    Also, check out this latest NORML PSA, featuring some great rhyming on the problems of prohibition, submitted to us from artist Will Brennan:
    [youtube]http://www.youtube.com/watch?v=jYN-qqbLq0M[/youtube]

    Be sure to tune in to NORMLtv every week to catch up on the latest marijuana news. Subscribe to NORMLtv or follow us on Twitter to be notified as soon as new content is added.

  • by Paul Armentano, NORML Deputy Director May 29, 2012

    [Editor’s note: This post is excerpted from this week’s forthcoming NORML weekly media advisory. To have NORML’s news alerts and legislative advisories delivered straight to your in-box, sign up here.]

    The use of cannabis is associated with lower mortality risk in patients with schizophrenia and related psychotic disorders, according to a forthcoming study to be published in the Journal of Psychiatric Research. (Read the abstract of the study online here.)

    An international team of investigators from the University of Maryland School of Medicine and Inje University in South Korea assessed the impact of a lifetime history substance use on mortality in 762 subjects with schizophrenia or related disorders.

    Researchers reported, “[W]e observed a lower mortality risk-adjusted variable in cannabis-users compared to cannabis non-users despite subjects having similar symptoms and anti-psychotic treatments.”

    Authors speculated that the association between marijuana use and decreased mortality risk may be because “cannabis users may (be) higher functioning” and because “cannabis itself may have some health benefits.”

    They concluded: “To our knowledge, this is one of the first studies to examine the risk of mortality with cannabis and alcohol in people with PD (psychotic disorders). This interesting finding of decreased mortality risk … in cannabis users is a novel finding and one that will need replication in larger epidemiological studies.”

    NORML Board Member Dr. Lester Grinpoon, psychiatrist and former Harvard Medical School professor, similarly noted that the study’s findings, though promising, require replication in separate trials. “In reading the cannabis literature over the years, I have learned to be somewhat skeptical about any single report and to maintain a ‘wait and see’ posture as new data eventually flesh out the reality,” he said.

    To date the association between cannabis use and psychotic disorders such as schizophrenia is not well understood. While some studies have associated cannabis use with higher cognitive functioning – including better performance on measures of processing speed and verbal skills – other research has implied that cannabis use, particularly heavy use at an early age, may precipitate or exacerbate the disease in those already vulnerable to it. Other experts have criticized this purported link to be “overstated” and not “particularly compelling,” noting that increased levels of cannabis use by the general public has not yet been positively associated with proportionally rising incidences of schizophrenia or other psychotic disorders.

    Full text of the study, “Alcohol and cannabis use and mortality in people with schizophrenia and related psychotic disorders,” will appear in the Journal of Psychiatric Research. Additional information on cannabis use and mental illness, please see the NORML white paper, “Cannabis, Mental Health, and Context.”

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